Coming of microgen 30 pill?

Iv been of microgen 30 for nearly 3 months now and still no sign of my period , I had my withdraw bleed a few days after stopping but nothing of the natural period , I keep having cramps but it's hard to tell what they mean , is this normal ?

I'm new to this website and I'm looking for advise too, ive been of the microgynon for around 5 weeks now, I had the same withdrawal bleed after finishing my last pack as normal, I've had cramps but no further periods. how long should you wait until visiting the doctors?